Times are stored internally by Excel as fractions of a 24-hour day, so
that 12:00:00 would be stored as 0.5 and 18:00:00 as 0.75.
Consequently, to convert a time to seconds, you must multiply by the
number of seconds in a day - it is easier to remember this as *24*60*60
rather than the actual number (86400).

Hope this helps.

Pete

wrote:
I would appreciate any help from an Excel guru out there that can help
me automatically convert a cell with a day:hours:minutes:seconds format
to seconds. So for example, 0:00:04:44 should be converted to 284.

Any ideas? Thanks in advance.